Mass extinction for Earth’s oceans probable, comprehensive study says

The first comprehensive study of its kind has determined that ocean life is facing mass extinction from human activity. But the record damage is still reversible – unlike our impact on land. American scientists say the effects can be mitigated.

We’ve known for a while that achieving sustainability would be
impossible with our lifestyles. Although the majority of Earth is
covered in water we are vastly reliant on, many of our practices
are causing unprecedented damage to marine biology: coral reef
damage, resource mining, fish farming, construction work,
chemical pollution, the depletion of bio resources, unintended
species migration, global warming, military drills – to name just
a few.

The picture has just been made clearer by a study that for the first time ever brought all these
strands together. Drs. Malin L. Pinsky, Stephen R. Palumbi,
Douglas J. McCauley and colleagues from the University of
California have dug into hundreds of sources past and present,
including the fossil record and statistics on shipping and seabed
mining to form the chilling conclusions of their study, published
Thursday in the journal Science.

“We may be sitting on a precipice of a major extinction
event,” McCauley says on the analysis, which has already
received wide acclaim from marine biologists and experts in
related fields.

One of the key conclusions is that the oceans had until now
largely evaded the damage we had caused to terrestrial life,
seeing as we’re after all a terrestrial species. But after 1800,
when industrialization hit, land extinction sped up and the stage
was set for irreversible water damage, which is now mirroring the
situation.

“Current trends in ocean use suggest that habitat destruction
is likely to become an increasingly dominant threat to ocean
wildlife over the next 150 years,” the team said in their
study. And because oceans are a fluid mechanism, and much more
difficult to monitor accurately than land, there is practically
no way of reaching a conclusion on the average state of Earth’s
water. Some places could be far wars off than others, hence the
importance of the new cumulative analysis.

We’re squeezing the species on all sides: mangrove farming
destroys habitats, while our fish nets have affected 20 million
square miles of ocean already, altering the continental shelf.

Seabed mining contracts are an especially huge change: the area
went from zero square miles in the year 2000 to a staggering
460,000 in 2014. This serious threat is especially dangerous to
sensitive and unique ecosystems.

And while we no longer hunt whales to the same extent, their
lives are now affected by a rapidly growing number of shipping
lanes.

The process is also a chain. The human footprint has caused a 40
percent decline in coral reefs worldwide, which consequently
leads to habitat destruction for marine species. Some migration
may result in the arrival of predatory species to ecosystems that
are not prepared to accept them, and so on. But everyone is
feeling the impact.

“If you cranked up the aquarium heater and dumped some acid
in the water, your fish would not be very happy,” Pinsky
said. “In effect, that’s what we’re doing to the
oceans.”

And it starts on land for many marine animals: some lay eggs –
like sea turtles; seabirds nest in cliffs, and so on. Some have
already become extinct due to our land activity.

“But in the meantime, we do have a chance to do what we can.
We have a couple decades more than we thought we had, so let’s
please not waste it,” Palumbi said. "I fervently believe
that our best partner in saving the ocean is the ocean
itself.”

McCauley elaborates that if we limit the industrialization of
Earth’s water, we could facilitate species recovery – much more
so than we ever could on land, where the damage is now
irreversible in places.

“There are a lot of tools we can use,” he said. The team
believes that designing an approach with climate change in mind
would be the way to go. It’s about considering how and where
species can escape rising temperatures and a lowering of pH
levels. As we learn that some areas are indeed affected more
gravely than others, one of the approaches may be to limit
industrial operations to some areas, while allowing others to
recover.

“It’s creating a hopscotch pattern up and down the coasts to
help these species adapt,” Pinsky said.